<p><strong>Scientists at IOCB Prague are uncovering new details of gene transcription. They have identified a previously unknown molecular mechanism by which the transcription of genetic information from deoxyribonucleic acid (DNA) into ribonucleic acid (RNA) can be initiated. The researchers focused on a specific class of molecules known as alarmones, which are found in cells across a wide range of organisms and whose levels often increase under conditions of cellular stress. The results were published in the prestigious scientific journal </strong><i><strong>Nature Chemical Biology</strong></i><strong>.</strong></p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_bc2bfffa6c.jpg" alt="IOCB Prague/Tomáš Belloň: Research from IOCB Prague reveals a previously unknown mechanism of genetic transcription: Dr. Hana Cahová, head of the Chemical Biology of Nucleic Acids research group." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_bc2bfffa6c.jpg 234w," sizes="100vw" width="2000" height="1335"></p><div><p>Molecules of ribonucleic acid can carry a variety of chemical modifications at one end, known as caps. In eukaryotic organisms, including human cells, the best-known cap plays an important role in RNA stability and in regulating its subsequent fate. In recent years, however, it has become clear that alternative, non-canonical RNA caps also exist, although their formation and the mechanisms by which they are attached to RNA remain only partially understood. These include alarmone caps, formed by dinucleoside polyphosphate molecules, that protect cellular RNA at moments when the cell is under threat.</p><p>In their study,<strong> </strong><a target="_blank" rel="noopener noreferrer" href="https://cahova.group.uochb.cz/en"><strong>Dr. Hana Cahová</strong></a> and colleagues examined bacterial RNA polymerase and investigated how this enzyme can initiate transcription using dinucleoside polyphosphates (NpNs) instead of the standard RNA building blocks. For the first time, the scientists described, at the atomic level, how RNA bearing an alarmone cap can be generated directly at the initiation of gene transcription. They also observed that NpNs bind through a different type of base pairing than is typically observed.</p><p>The work was significantly shaped by <strong>Valentina Serianni from Hana Cahová’s team</strong>, who demonstrated the ability of dinucleoside polyphosphates to initiate gene transcription, and by <strong>Jana Škerlová</strong>, who focused on the structural analysis of RNA polymerase. Using cryogenic electron microscopy data, she showed how dinucleoside polyphosphate molecules bind within the active site of RNA polymerase – that is, the core of the enzyme where genetic information is transcribed. Together, their findings help to elucidate the processes that accompany the transcription of genetic information from DNA to RNA.</p><p>Hana Cahová adds: <i>“We’re describing something that truly occurs in cells and that we’re now able to observe directly at the level of individual molecules. This allows us to answer fundamental questions about cellular processes, such as how cells adapt to stress. RNA plays a central role in this, as it carries the cascade of information underlying any cellular response – for example, to threatening conditions caused by nutrient deprivation or temperature shock.”</i></p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_2_0fe88ff9e9.jpg" alt="IOCB Prague/Tomáš Belloň: Research from IOCB Prague reveals a previously unknown mechanism of genetic transcription: Dr. Tomáš Kouba, head of the Cryogenic Electron Microscopy core facility." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_2_0fe88ff9e9.jpg 234w," sizes="100vw" width="2000" height="1335"></p><div><p>Cryogenic electron microscopy (cryo-EM) was central to the project. This part of the work was led by<strong> Dr. Tomáš Kouba</strong>, one of the authors of the study. <i>“Cryogenic electron microscopy allows us to freeze biological molecules in a state very close to their natural form and then determine their three-dimensional structure. This makes it possible to look directly into the active centers of enzymes and observe their function down to the atomic level,”</i> he explains.</p><p>Last year, IOCB Prague opened a new <a target="_blank" rel="noopener noreferrer" href="https://cryoem.group.uochb.cz/en"><strong>cryo-EM center</strong></a><strong> </strong>that is unique within the Czech research environment. State-of-the-art cryogenic electron microscopes are housed in a specially designed building and enable the study of biological processes with exceptional structural precision.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_3_4d881e7a58.jpg" alt="IOCB Prague: Research from IOCB Prague reveals a previously unknown mechanism of genetic transcription: This work shows how NpnNs initiate bacterial transcription. Cryo-EM reveals how nucleobases pair with the template: one in canonical and one in reverse Watson–Crick mode, providing a structural basis for their function as non-canonical RNA caps." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_UOCHB_Vyzkum_z_UOCHB_odhaluje_dosud_nepoznany_zpusob_prepisu_geneticke_informace_3_4d881e7a58.jpg 245w," sizes="100vw" width="2000" height="1077"></p><blockquote><h4><strong>The Original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://www.nature.com/articles/s41589-025-02134-5"><strong>Molecular insight into 5′ RNA capping with Np<sub>n</sub>Ns by bacterial RNA polymerase</strong></a></h4><p>Valentina M. Serianni, Jana Škerlová, Anna Knopp Dubánková, Anton Škríba, Hana Šváchová, Tereza Vučková, Anatolij Filimoněnko, Milan Fábry, Pavlína Řezáčová, Tomáš Kouba &amp; Hana Cahova&nbsp;</p><p>Nat. Chem. Biol. 21 (2026)</p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1038/s41589-025-02134-5">https://doi.org/10.1038/s41589-025-02134-5</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><h4><strong>Abstract</strong></h4><p>RNA capped with dinucleoside polyphosphates has been discovered in bacteria and eukaryotes only recently. The likely mechanism of this specific capping involves direct incorporation of dinucleoside polyphosphates by RNA polymerase as noncanonical initiating nucleotides. However, how these compounds bind into the active site of RNA polymerase during transcription initiation is unknown. Here, we explored transcription initiation in vitro, using a series of DNA templates in combination with dinucleoside polyphosphates and model RNA polymerase from <i>Thermus</i> <i>thermophilus</i>. We observed that the transcription start site can vary on the basis of the compatibility of the specific template and dinucleoside polyphosphate. Cryo-electron microscopy structures of transcription initiation complexes with dinucleoside polyphosphates revealed that both nucleobase moieties can pair with the DNA template. The first encoded nucleotide pairs in a canonical Watson–Crick manner, whereas the second nucleobase pairs noncanonically in a reverse Watson–Crick manner. Our work provides a structural explanation of how dinucleoside polyphosphates initiate RNA transcription.</p></div></div>

Research from IOCB Prague reveals a previously unknown mechanism of genetic transcription

<p><strong>In the week of February 9, the following webinars await you in the field of gas / solid phase and especially Raman, FTIR, GC and GC/MS.</strong></p><blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinars"><strong>👉 DETAILS AND REGISTRATION IN THE WEBINARS SECTION</strong></a></h4><p><strong>👉 Search and filter in the largest global database</strong> with over <strong>5 000 GC, LC, MS and spectroscopy webinars</strong>.</p></blockquote><div><div><div><div><div><div><h5><strong>1. Thermo Fisher Scientific: Process Raman – A Reliable and Versatile Tool for Downstream Process Monitoring and Control for mAb Production</strong></h5><ul><li>Tu, 10.2.2026 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5808">Registration</a></li></ul><p>The presentation highlights how process Raman spectroscopy offers several advantages over traditional in-line UV-Vis analysis for process monitoring and metabolite production control in mAb manufacturing.</p><h5><strong>2. Wasson-ECE Instrumentation: The Data Driven Plant – How AI Transforms Chemical Manufacturing</strong></h5><ul><li>Tu, 10.2.2026 21:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5744">Registration</a></li></ul><p>Explore how artificial intelligence is applied to improve process efficiency, monitoring, and decision-making in modern chemical manufacturing.</p><h5><strong>3. New Food Magazine: The Science of Next-Gen Ingredients – Fermentation, Formulation and Function</strong></h5><ul><li>We, 11.2.2026 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5720">Registration</a></li></ul><p>Discover how fermentation-driven innovation is transforming functional food ingredients, with analytical insights to optimize flavour, functionality, and product stability.</p></div></div></div></div></div></div>

Webinars LabRulezGCMS Week 07/2026

<p><strong>This study presents an analytical strategy combining QuEChERS extraction with low-temperature partitioning (LTP) for the determination of multiclass pesticide residues in cocoa beans by GC–MS. Extraction conditions were optimized using a fractional factorial design, resulting in a simple and efficient workflow suitable for complex cocoa matrices.</strong></p><p>The validated method showed satisfactory limits of detection and quantification, recoveries within 70–120%, and good overall performance. Application to cocoa samples from Brazil detected permethrin in several samples, demonstrating that the QuEChERS–LTP approach is an effective and reliable cleanup strategy for routine pesticide residue analysis in cocoa.</p><blockquote><h4><strong>The original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360"><strong>QuEChERS Combined with Low-Temperature Partitioning and GC–MS as an Analytical Strategy for the Determination of Multiclass Pesticide Residues in Cocoa Beans</strong></a></h4><p>Priscilla M. de Freitas Machado, Madson M. Nascimento, Paulo R. R. Mesquita, Manuela B. Nascimento, Lilian Lefol N. Guarieiro, Gisele O. da Rocha, Jailson B. de Andrade, Raildo M. de Jesus*</p><p>ACS Omega 2025, 10, 51, 63464–63473</p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acsomega.5c10360">https://doi.org/10.1021/acsomega.5c10360</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><p><strong>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.</strong></p><p>Cocoa is best known as the primary raw material for chocolate but is also processed into products such as cocoa butter, biscuits, cocoa honey, and cocoa powder. Cocoa powder is derived from roasted, pressed, and milled nibs, containing on average 20% (w/w) lipids on a dry basis and less than 9% moisture. <a href="javascript:void(0);">(3,4)</a></p><p>According to the Brazilian Health Regulatory Agency (ANVISA), pesticides such as atrazine, bifenthrin, cyproconazole, metalaxyl, tebuconazole, trifloxystrobin, and permethrin are approved for use in Brazil. <a href="javascript:void(0);">(13)</a> However, among these, only metalaxyl, trifloxystrobin, and tebuconazole are authorized by the European Union. <a href="javascript:void(0);">(14)</a> Thus, investigating these contaminants in cocoa samples is of utmost importance, as Brazil is one of the largest cocoa exporters, supplying cocoa commodities to South America, the United States, and the European Union. <a href="javascript:void(0);">(2)</a> Furthermore, Organochlorine pesticides, in particular, belong to the class of persistent organic pollutants (POPs). Although banned in many countries, they continue to be used in some developing nations because of their chemical stability, resistance to degradation, volatility, and high lipophilicity, which promote bioaccumulation and neurotoxicity. <a href="javascript:void(0);">(15)</a> Epidemiological evidence also associates their exposure with Parkinson’s disease, certain cancers, diabetes, and endometriosis. <a href="javascript:void(0);">(16)</a></p><p>Residues of pesticides in cocoa have been reported in various studies. <a href="javascript:void(0);">(17)</a> Analyzing pesticide residues in cocoa presents analytical challenges due to the matrix’s complexity, comprising high lipid content, fatty acids and esters, sugars, polyphenols, and caffeine. These components can interfere with extraction efficiency and contaminate analytical instrumentation. <a href="javascript:void(0);">(18)</a> Therefore, efficient sample preparation methods incorporating effective cleanup steps are essential for accurate residue determination.</p><p>Several techniques have been employed for multiresidue pesticide analysis in cocoa. For instance, Idowu et al. <a href="javascript:void(0);">(19)</a> quantified 14 organochlorines using Soxhlet extraction and silica/Na<sub>2</sub>SO<sub>4</sub> cleanup, with GC ECD detection. Okoffo et al. <a href="javascript:void(0);">(20)</a> determined 13 organophosphates and 9 pyrethroids employing SPE cartridges (Envi-carb/LC-NH<sub>2</sub> and Bond Elute C18), acetonitrile extraction, and GC PFPD or GC ECD quantification. Yusiasih et al. <a href="javascript:void(0);">(21)</a> applied dispersive SPE with PSA, Florisil, and MgSO<sub>4</sub> for pyrethroids, followed by GC ECD and GC–MS.</p><p>Therefore, this study aimed to evaluate the effectiveness of a QuEChERS–LTP analytical procedure for the determination of multiclass pesticide residues in cocoa beans. The factors that affect the QuEChERS–LTP procedure efficiency were optimized. After validation, the procedure was employed to investigate the occurrence of 15 multiclass pesticides in cocoa samples.</p><h4><strong>Experimental Section</strong></h4><h5><strong>Instrumental Apparatus</strong></h5><p>Pesticide separation and identification were performed on a Shimadzu <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GC-MS-QP2010SE"><strong>GC-MS-QP2010SE</strong></a> system (Kyoto, Japan) equipped with an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=AOC-20i"><strong>AOC-20i autosampler</strong></a>. Separation was achieved using an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=DB-5MS"><strong>Agilent DB-5MS capillary column</strong></a> (30 m × 0.25 mm × 0.25 μm) with a stationary phase of 5% phenyl/95% dimethylpolysiloxane. The instrumental conditions were based on Nascimento et al. <a href="javascript:void(0);">(49)</a> and they are summarized in <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#tbl4">Table 4</a>.</p><p>For quantification, the base peak was used, while two additional ions were monitored for confirmation (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acsomega.5c10360/suppl_file/ao5c10360_si_001.pdf">Table S2</a>) in accordance with SANTE guidelines. <a href="javascript:void(0);">(50)</a> A GC–MS/SIM chromatogram illustrating the separation of all target pesticides is presented in <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#fig5">Figure 5</a>.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_51_63464_63473_Figure_5_Extracted_ion_chromatogram_EIC_in_SIM_mode_of_the_target_pesticides_f2461c14f4.jpg" alt="ACS Omega 2025, 10, 51, 63464–63473: Figure 5. Extracted ion chromatogram (EIC) in SIM mode of the target pesticides obtained from the injection of a mixed standard solution at 100 μg L–1. Analytes are listed in order of elution: [1] Molinate (6.18 min); [2] α-HCH (8.15 min); [3] atrazine-d5 (8.69 min); [4] atrazine (8.75 min); [5] diazinon (9.31 min); [6] disulfoton (9.67 min); [7] dimethachlor (10.60 min); [8] metalaxyl (11.25 min); [9] p,p′-DDE (15.82 min); [10] cyproconazole I (16.50 min); [11] cyproconazole II (16.56 min); [12] p,p′-DDD (17.29 min); [13] ethion (17.34 min); [14] trifloxystrobin (18.43 min); [15] tebuconazole (19.13 min); [16] bifenthrin (20.47 min); [17] permethrin I (23.92 min); [18] permethrin II (24.18 min)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_51_63464_63473_Figure_5_Extracted_ion_chromatogram_EIC_in_SIM_mode_of_the_target_pesticides_f2461c14f4.jpg 245w," sizes="100vw" width="2080" height="835"></p><h5><strong>Application of the Proposed Procedure to Real Samples</strong></h5><p>In a 50 mL Falcon tube, 2.0 g of sample was weighed using an analytical balance (AUX320, Shimadzu, Kyoto, Japan). A total of 2.0 g of salt (NaCl and Na<sub>2</sub>SO<sub>4</sub> in a 1:1 w/w ratio) was added, followed by an aliquot of the atrazine-<i>d</i><sub>5</sub> solution (surrogate standard) to yield a final concentration of 250 μg kg<sup>–1</sup>. A mixture of acetonitrile (8.0 mL) and ultrapure water (2.0 mL) was then added. The system was vortexed (K40-10208, Kasvi, São Paulo, Brazil) for 3.0 min at 2500 rpm and centrifuged (MPW-351R, MPW Med. Instruments, Warsaw, Poland) for 10.0 min at 15 °C and 10,000 rpm. After phase separation, approximately 6.0 mL of the supernatant was transferred to a Falcon tube containing 150.0 mg of PSA sorbent. The mixture was vortexed again for 3.0 min at 2500 rpm and centrifuged for an additional 10.0 min under the same conditions. The tubes were then placed in the freezer for 24 h. Once the aqueous phase had frozen, the organic extract containing the analytes was collected, filtered through a Cytiva Whatman MiniUniprep G2 vial with a 0.20 μm membrane filter (Marlborough, Massachusetts, USA), and injected into the GC–MS system (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#fig6">Figure 6</a>).</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_51_63464_63473_Figure_6_Schematic_representation_of_the_extraction_procedure_using_the_Qu_E_Ch_ERS_LTP_procedure_for_pesticide_extraction_in_cocoa_powder_samples_ed58549bcf.jpg" alt="ACS Omega 2025, 10, 51, 63464–63473: Figure 6. Schematic representation of the extraction procedure using the QuEChERS–LTP procedure for pesticide extraction in cocoa powder samples." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_51_63464_63473_Figure_6_Schematic_representation_of_the_extraction_procedure_using_the_Qu_E_Ch_ERS_LTP_procedure_for_pesticide_extraction_in_cocoa_powder_samples_ed58549bcf.jpg 223w," sizes="100vw" width="1458" height="1022"></p><h4><strong>Results and Discussion</strong></h4><h5><strong>Evaluation of the Effect of Low and Ultralow Temperatures on the Analytical Response</strong></h5><p>Studies reporting the use of LTP generally employ a conventional freezer, which typically reaches −18 ± 2 °C as the minimum temperature. In this equipment, effective phase separation can require 8 to 24 h. <a href="javascript:void(0);">(35−37)</a> In contrast, ultralow temperature freezers (ultrafreezers) can reach −80 °C, leading to a substantial reduction in partitioning time. In this study, tests performed with the conventional freezer achieved satisfactory partitioning after 24 h, whereas in the ultrafreezer, complete partitioning was observed in only 20 min.</p><p>Considering the analytical response in terms of peak area (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#fig3">Figure 3</a>), higher signals were obtained when LTP was performed in a conventional freezer rather than an ultrafreezer. This behavior can be attributed to the partitioning mechanism. <a href="javascript:void(0);">(32)</a> Partitioning depends on cooling and the subsequent freezing of the aqueous phase. In the conventional freezer, the slower freezing rate provides sufficient time for the system to approach thermodynamic equilibrium, favoring analyte diffusion between phases. Under these conditions, analyte molecules have more time to migrate and distribute optimally before complete solidification. In contrast, the rapid freezing in the ultrafreezer may trap analytes in a nonideal distribution, reducing the efficiency of the partitioning process <a href="javascript:void(0);">(32)</a> (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#fig3">Figure 3</a>). According to these observations, the conventional freezer was selected for subsequent experiments.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_51_63464_63473_Figure_3_Comparison_of_chromatographic_peak_areas_of_pesticides_after_partitioning_in_the_conventional_freezer_versus_the_ultrafreezer_9598bcfec3.jpg" alt="ACS Omega 2025, 10, 51, 63464–63473: Figure 3. Comparison of chromatographic peak areas of pesticides after partitioning in the conventional freezer versus the ultrafreezer." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_51_63464_63473_Figure_3_Comparison_of_chromatographic_peak_areas_of_pesticides_after_partitioning_in_the_conventional_freezer_versus_the_ultrafreezer_9598bcfec3.jpg 175w," sizes="100vw" width="996" height="891"></p><h5><strong>Application to Real Samples</strong></h5><p>Fifteen samples were analyzed in triplicate, comprising two from the State of Pará and 12 from the State of Bahia, located in the North and Northeast regions of Brazil, respectively. Among the 15 pesticides investigated, only permethrin isomers were quantified in four samples (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#tbl3">Table 3</a>). The herbicide molinate was also detected in three samples; however, its concentration was below LOQ. Permethrin isomers concentrations ranged from 17.1 ± 0.3 to 49.6 ± 1.8 μg kg<sup>–1</sup>. These values are below the MRL established by European Union regulation, which is 100 μg kg<sup>–1</sup>. <a href="javascript:void(0);">(42)</a> Although permethrin is not permitted in the European Union, <a href="javascript:void(0);">(42)</a> it remains authorized for use as insecticide in Brazil, particularly in crops such as cotton, rice, coffee, citrus, cabbage, beans, tobacco, maize, soybean, tomato, wheat, and grape. <a href="javascript:void(0);">(13)</a> However, no MRL values have been established for cocoa beans under Brazilian legislation. <a href="javascript:void(0);">(13)</a> <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c10360#tbl3">Table 3</a> shows the concentration of detected compounds in the cocoa samples.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_51_63464_63473_Table_3_Mean_Concentrations_mg_kg_1_Standard_Deviation_of_Target_Pesticides_Detected_in_This_Study_2427955699.jpg" alt="ACS Omega 2025, 10, 51, 63464–63473: Table 3. Mean Concentrations (μg kg–1 ± Standard Deviation) of Target Pesticides Detected in This Study" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_51_63464_63473_Table_3_Mean_Concentrations_mg_kg_1_Standard_Deviation_of_Target_Pesticides_Detected_in_This_Study_2427955699.jpg 196w," sizes="100vw" width="1070" height="851"></p><p>To assess method performance for pesticides not detected in the cocoa samples, one of the analyzed samples was fortified with a mixed standard solution at concentrations of 50, 250, and 500 μg kg<sup>–1</sup>. The fortified analytes were subsequently detected in the chromatograms presented in <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acsomega.5c10360/suppl_file/ao5c10360_si_001.pdf">Figures S2–S4</a>, indicating good response of the proposed method.</p><h4><strong>Conclusions</strong></h4><p>The QuEChERS–LTP procedure was successfully developed for the determination of 16 multiclass pesticide residues in cocoa beans. For the first time, ultralow temperature (−80 °C) was applied to accelerate the low-temperature partitioning process during pesticide extraction from cocoa beans. Nevertheless, conventional freezing at −12 °C proved to be more effective for the extraction of the target analytes.</p><p>Evaluation of the matrix effect demonstrated that matrix-matched analytical curves, constructed in an analyte-free cocoa bean extract, were more effective in compensating for matrix interferences than the use of analyte protectants.</p><p>The pyrethroid permethrin was quantified in four cocoa samples. However, the concentrations did not exceed the MRL established by European Union legislation.</p><p>Overall, the QuEChERS–LTP procedure proved to be a promising approach for pesticide residue determination, as it requires smaller volumes of solvents and reagents, involves fewer cleanup and extraction steps, and shows strong potential for application to other complex matrices.</p>

QuEChERS Combined with Low-Temperature Partitioning and GC–MS as an Analytical Strategy for the Determination of Multiclass Pesticide Residues in Cocoa Beans

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The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences (IOCB Prague) is a leading scientific institution in the Czech Republic, recognized internationally. Its primary mission is basic research in the fields of chemical biology and medicinal chemistry, organic and material oriented chemistry, chemistry of natural compounds, biochemistry and molecular biology, physical chemistry, theoretical chemistry, and analytical chemistry. 

Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences

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<p><strong>The Pegasus BT GC-TOFMS is a compact, high-performance benchtop gas chromatography time-of-flight mass spectrometer designed to deliver comprehensive chemical information with exceptional sensitivity, speed, and reliability. It combines advanced TOF mass spectrometry hardware with LECO’s powerful </strong><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/41"><strong>ChromaTOF® software</strong></a><strong> to support both routine and advanced analytical workflows.</strong></p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_Pegasus_BT_2_bc8a8d0505.jpg" alt="LECO PEGASUS BT GC-TOFMS" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_Pegasus_BT_2_bc8a8d0505.jpg 238w," sizes="100vw" width="932" height="612"></p><p>Designed for laboratories that need to analyze more samples, generate more data, and achieve results faster, the Pegasus BT acquires full-range mass spectral data in every run—ensuring that no analytes are missed, even in highly complex matrices. Industry-leading sensitivity, combined with <strong>NonTarget Deconvolution® (NTD®)</strong>, enables confident identification and quantification of both known and unknown compounds by effectively separating co-eluting peaks and minimizing matrix interferences.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_GC_TOFMS_7_be16be31ec.jpg" alt="LECO PEGASUS BT GC-TOFMS: NonTarget Deconvolution® (NTD®) Automated deconvolution ensures that coeluting peaks and matrix interferences don't hinder your analyses.StayClean Ion Source Open-style EI source virtually eliminates downtime associated with source cleaning*, which means you can spend your time running more samples.  *Even after 3,000 sludge injections, source has not needed cleaning." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_GC_TOFMS_7_be16be31ec.jpg 245w," sizes="100vw" width="768" height="432"></p><p>The system features LECO’s proven <strong>StayClean® open-style EI ion source</strong>, which virtually eliminates downtime associated with source cleaning and allows extended operation even with challenging sample matrices. Its compact benchtop footprint makes the Pegasus BT an ideal solution for laboratories with limited space, without compromising analytical performance.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_GC_TOFMS_6_047f81e642.jpg" alt="LECO PEGASUS BT GC-TOFMS: " srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_GC_TOFMS_6_047f81e642.jpg 245w," sizes="100vw" width="616" height="375"></p><p>Fully integrated <strong>ChromaTOF® software</strong> provides automated deconvolution, quantification, reporting, batch processing, and long-term data mining. The Pegasus BT GC-TOFMS is ideally suited for pesticide analysis, metabolomics, petroleum and fuel characterization, food, flavor, and fragrance analysis, and other demanding GC-MS applications.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_GC_TOFMS_2_cc1a963b9e.jpg" alt="LECO PEGASUS BT GC-TOFMS: ChromaTOF® software" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_GC_TOFMS_2_cc1a963b9e.jpg 245w," sizes="100vw" width="943" height="566"></p><h3><strong>Key Features</strong></h3><ul><li><strong>Benchtop GC-TOFMS</strong> with full-range mass spectral acquisition in every analysis</li><li><strong>Industry-leading sensitivity</strong> for trace-level detection</li><li><strong>NonTarget Deconvolution® (NTD®)</strong> for reliable separation of co-eluting compounds and suppression of matrix interferences</li><li><strong>StayClean® open-style EI ion source</strong> for minimal maintenance and reduced downtime</li><li><strong>High sample throughput with excellent repeatability</strong></li><li><strong>Compact footprint </strong>with uncompromised analytical performance</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_GC_TOFMS_5fd6d4a332.jpg" alt="LECO PEGASUS BT GC-TOFMS" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_GC_TOFMS_5fd6d4a332.jpg 245w," sizes="100vw" width="1220" height="591"></p><h3><strong>Applications</strong></h3><ul><li>Pesticides and environmental contaminants</li><li>Petroleum products, fuels, and fuel marker analysis</li><li>Metabolomics and non-target screening</li><li>Food, flavor, and fragrance analysis</li><li>Characterization of complex matrices and unknown identification</li></ul><h5><strong>&nbsp;Calibration curve in strawberry matrix: Cyprodinil</strong></h5><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_GC_TOFMS_3_6a4f0ecc50.jpg" alt="LECO PEGASUS BT GC-TOFMS: The calibration curve at left shows excellent linearity, and sensitivity easily meets all standard requirements." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_GC_TOFMS_3_6a4f0ecc50.jpg 245w," sizes="100vw" width="871" height="480"></p><h5><strong>Characterization of fuel markers at trace levels is easy and routine</strong></h5><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_GC_TOFMS_4_33217d7f2e.jpg" alt="LECO PEGASUS BT GC-TOFMS: Full TIC chromatogram of a spiked commercial diesel sample." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_GC_TOFMS_4_33217d7f2e.jpg 237w," sizes="100vw" width="742" height="489"></p>

LECO PEGASUS BT 4D GC×GC-TOFMS

LECO PEGASUS BT 4D GC×GC-TOFMS combines comprehensive two-dimensional GC with fast TOFMS to improve separation, sensitivity, and confidence in qualitative and quantitative analysis of complex samples.

<p><strong>The LECO PEGASUS BT 4D GC×GC-TOFMS is a high-performance benchtop system that combines comprehensive two-dimensional gas chromatography (GC×GC) with time-of-flight mass spectrometry (TOFMS) to deliver unmatched separation power, sensitivity, and confidence in compound identification. Designed for laboratories facing highly complex samples, the PEGASUS BT 4D enables qualitative and quantitative analysis in a single run while maximizing productivity and data quality.</strong></p><p>By coupling GC×GC separation with fast TOFMS acquisition, the system <strong>dramatically increases chromatographic peak capacity and resolves co-eluting compounds </strong>that are difficult or impossible to distinguish by conventional 1D GC-MS. Enhanced signal-to-noise ratios translate into lower detection limits, improved linearity, and more reliable quantification—even in challenging matrices.</p><h3><strong>What GC×GC Brings to Your Analysis</strong></h3><p>GC×GC modulation refocuses and reinjects analytes from the first column into a second column with a different stationary phase, providing structured chromatograms that improve interpretability of complex data. This approach improves both separation efficiency and interpretability of results, allowing you to identify more compounds with greater confidence and consistency.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_c9ad0bd186.jpg" alt="LECO PEGASUS BT 4D GC×GC-TOFMS" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_c9ad0bd186.jpg 245w," sizes="100vw" width="1029" height="594"></p><h3><strong>Confident Identification and Quantification</strong></h3><p>The PEGASUS BT 4D excels in both comprehensive screening and targeted applications. Spectral deconvolution combined with high-speed TOFMS acquisition reveals analytes present in complex matrices, while GC×GC separation minimizes matrix interferences for superior quantitative performance. What was once a marginal library match in GC-MS becomes a confident identification in GC×GC-TOFMS.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_2_4e033e866c.jpg" alt="LECO PEGASUS BT 4D GC×GC-TOFMS: Quantitative analysis using the Pegasus BT 4D" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_2_4e033e866c.jpg 245w," sizes="100vw" width="1443" height="637"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_3_18eebd600d.jpg" alt="LECO PEGASUS BT 4D GC×GC-TOFMS: Qualitative analysis using the Pegasus BT 4D" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_3_18eebd600d.jpg 210w," sizes="100vw" width="1442" height="1069"></p><h3><strong>Robust Design for High-Throughput Labs</strong></h3><p>Equipped with LECO’s proven StayClean® ion source, the PEGASUS BT 4D minimizes routine maintenance and downtime, even when analyzing dirty or complex samples. Integrated with <strong>ChromaTOF®</strong> software, the system provides seamless instrument control, automated data processing, and powerful qualitative and quantitative tools within a single platform.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_c2644cd38e.jpg" alt="LECO - PEGASUS BT 4D GCxGC-TOFMS.jpg" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_c2644cd38e.jpg 202w," sizes="100vw" width="1099" height="849"></p><h3><strong>Key Benefits</strong></h3><ul><li>Exceptional chromatographic resolution and peak capacity with GC×GC</li><li>Enhanced sensitivity and lower detection limits through modulation-based signal focusing</li><li>High-speed TOFMS acquisition for accurate deconvolution of narrow GC×GC peaks</li><li>Reliable identification and quantification of analytes</li><li>Reduced maintenance with the StayClean® ion source</li><li>Fully integrated ChromaTOF® software for acquisition, processing, and reporting</li></ul><h3><strong>Applications</strong></h3><p>The LECO PEGASUS BT 4D GC×GC-TOFMS is ideally suited for demanding applications across environmental analysis, petrochemical and energy research, food and flavor/fragrance analysis, forensics, life sciences, and metabolomics—anywhere complex mixtures require maximum separation power and analytical confidence.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_4_8e8ec115ec.jpg" alt="LECO PEGASUS BT 4D GCxGC-TOFMS: Excellent Sensitivity" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_4_8e8ec115ec.jpg 244w," sizes="100vw" width="974" height="625">With the PEGASUS BT 4D, you can <strong>predict, quantify, and identify more compounds with confidence</strong>, turning complex data into clear, actionable results.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_5_625fed2f0d.jpg" alt="LECO PEGASUS BT 4D GCxGC-TOFMS: Identify MORE with confidence/non-target analysis" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_PEGASUS_BT_4_D_G_Cx_GC_TOFMS_5_625fed2f0d.jpg 240w," sizes="100vw" width="1034" height="672"></p>

LECO Pegasus GC-HRT+

Ultra-high-resolution GC-TOFMS with up to 50,000 FWHM, <1 ppm mass accuracy, and 200 spectra/s. Pegasus GC-HRT+ delivers unmatched sensitivity and confident identification in complex samples.

<p><strong>Now with even higher sensitivity, the Pegasus GC-HRT+ is designed to meet the most demanding analytical challenges. This high-performance GC-TOFMS delivers industry-leading mass accuracy, full-range acquisition at exceptional speed, precise isotopic abundance, and ultra-high mass resolution—all within a single injection.</strong></p><p>Folded Flight Path (FFP) technology combined with a novel data acquisition system enables up to <strong>50,000 FWHM resolution</strong>, <strong>&lt;1 ppm mass accuracy</strong>, and <strong>acquisition rates up to 200 spectra/s</strong>, supporting rich analyte discovery and high-confidence identification in highly complex samples.</p><h3><strong>Key features</strong></h3><ul><li><strong>Mass accuracy ≤1 ppm</strong> with peak capacity at least <strong>2× higher</strong> than conventional MS platforms</li><li><strong>Encoded Frequent Pushing (EFP)</strong> for markedly increased sensitivity, expanded dynamic range, and wide mass range</li><li><strong>Folded Flight Path (FFP)</strong> technology for ultra-high resolution, enhanced sensitivity, and advanced TOF focusing</li><li><strong>KADAS®</strong> ion-statistics-based acquisition to reduce noise, ensure mass accuracy, and minimize file size</li><li><strong>Ultra High Resolution + HRD</strong> to resolve highly isobaric ions (mass differences ~0.02 amu)</li><li><strong>Multi-Mode Source (MMS):</strong> EI, Positive CI, and ECNI in one system</li></ul><h3><strong>Models</strong></h3><ul><li><strong>Pegasus GC-HRT+</strong> – Full-scale GC-TOFMS</li></ul><h3><strong>Options</strong></h3><ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/82"><strong>L-PAL3 Automated Sample Injector</strong></a></li></ul>

LECO Pegasus GC-HRT+ 4D

High-resolution GC×GC-TOFMS system combining extreme separation power, up to 200 spectra/s acquisition, and advanced HR deconvolution for confident identification of unknowns in complex samples.

<p><strong>The Pegasus GC-HRT+ 4D from </strong><span><strong>LECO</strong></span><strong> combines comprehensive two-dimensional gas chromatography (GC×GC) with high-resolution time-of-flight mass spectrometry (TOFMS) and advanced High-Resolution Deconvolution (HRD). Designed for the most complex sample matrices, the system enables detection, separation, and confident identification of more analytes than ever before. </strong><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/41"><strong>ChromaTOF® software</strong></a><strong>, purpose-built for HRT+ instrumentation and GC×GC workflows, integrates advanced qualitative and quantitative tools into a single, user-friendly data system.</strong></p><h3><strong>Key Features</strong></h3><ul><li><strong>Compact benchtop design</strong> that saves valuable laboratory space</li><li><strong>Industry-leading sensitivity</strong> with proprietary deconvolution algorithms for clean, high-quality spectra</li><li><strong>High acquisition speed</strong> up to 200 spectra/s to properly define ultra-narrow GC×GC peaks (&lt;200 ms)</li><li><strong>Complete historical mass-spectral record</strong> retained for future data mining and reprocessing</li><li><strong>Proven Pegasus reliability and durability</strong> in a modern, space-efficient format</li></ul><h3><strong>GC×GC Performance Explained</strong></h3><p>GC×GC achieves exceptionally high peak capacity by trapping compounds eluting from the first column and reinjecting them into a second column for rapid secondary separation. These second-dimension separations occur within seconds, producing extremely narrow peaks that demand very high spectral acquisition rates. The Pegasus GC-HRT+ 4D meets and exceeds this requirement, enabling robust spectral deconvolution and confident compound identification in highly complex samples.</p><h3><strong>Available Configurations</strong></h3><ul><li><strong>Pegasus GC-HRT+ 4D with Liquid Nitrogen Thermal Modulator</strong></li><li><strong>Pegasus GC-HRT+ 4D with Cryogen-Free Modulator</strong></li></ul><h3><strong>Optional Accessories</strong></h3><ul><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/82"><strong>L-PAL3 Autosampler</strong></a></li></ul>

LECO ChromaTOF Software

ChromaTOF is LECO’s advanced GC and GC×GC analytical software, offering fully integrated instrument control, powerful deconvolution, and high-end qualitative and quantitative analysis for TOFMS data.

<p><strong>ChromaTOF is proprietary analytical software developed by </strong><span><strong>LECO</strong></span><strong> specifically for GC-TOFMS and GC×GC-TOFMS workflows. It is purpose-built to handle the extremely large datasets generated by time-of-flight mass spectrometers and to fully support multidimensional chromatography (GC×GC) in a single, integrated data system.</strong></p><p>ChromaTOF provides seamless instrument and accessory control, highly integrated qualitative and quantitative data processing, and an intuitive user interface. It was the first mass spectrometry data system to natively accommodate GC×GC data and remains a reference platform for advanced GC and GC×GC analysis.</p><h3><strong>What Makes ChromaTOF Unique</strong></h3><ul><li>Automatic saving of all data processing steps directly within the file system</li><li>Integrated storage and management of metadata and instrument data</li><li>All standard features included in a single software package</li><li>Built-in control for compatible options, activated only when needed</li><li>Easy-to-use yet powerful, efficient, and robust environment</li><li>Frequent updates for maintenance improvements and new functionality</li></ul><p>ChromaTOF combines advanced qualitative and quantitative capabilities in one user-friendly platform and supports both <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products?category=21&amp;manufacturerItems=24&amp;search=bt"><strong>Pegasus BT</strong></a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/38"><strong>Pegasus GC-HRT</strong></a> instrument families.</p><h3><strong>What Can ChromaTOF Do</strong></h3><ul><li>Automatic tuning with report generation</li><li>Absolute quantitation using calibration curves</li><li>Relative quantitation based on reference or analyte curves</li><li>Quantitation using single-channel detectors (FID)</li><li>Importable workspace templates to speed up setup</li><li>Spectral deconvolution with library searches (NIST, Wiley, or user libraries)</li><li>Semi-quantitative analysis of non-calibrated compounds</li><li>Integrated control of LECO and Agilent sample handling systems</li><li>Automatic export to CSV, ANDI MS, NETCDF, or LECO formats</li><li>Compatibility with liquid nitrogen and consumable-free <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/44"><strong>GC×GC thermal modulators</strong></a></li><li>GC×GC classification and method development tools</li><li>Integrated GC control</li><li>Unknown-unknown discovery using ChemSpider</li><li>Advanced calculation tools:<ul><li>Monoisotopic mass from molecular formula</li><li>Formula generation from measured mass</li><li>Required mass resolution for separating close masses</li></ul></li></ul><p><strong>Licensing options:</strong> 90-day free trial, 1-year subscription, or perpetual license.</p><h3><strong>Exclusive Features for Pegasus High-Resolution Models</strong></h3><ul><li>Automated unknown identification using High-Resolution Deconvolution</li><li>Automatic fragment formula generation with mass accuracy reporting</li><li>Accurate <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/application::paper.paper/SEP_SCI_ACCURATE_MASS_LIBRARY_209-272.pdf"><strong>Mass Spectral Libraries</strong></a> with AML Rank similarity scoring</li><li>User-scalable mass defect plots (e.g., Kendrick mass defect)</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/application::paper.paper/SPECTRAL_ANALYSIS_TOOL_SAT_209-262.pdf"><strong>Optional Spectral Analysis Tool</strong></a> with Van Krevelen and CN vs. RDBE plots</li></ul><h3><strong>Features for Pegasus Benchtop Models</strong></h3><ul><li>Automated unknown identification using Non-Target Deconvolution</li><li>Full profile mass spectra acquisition at 35 kHz with better-than-nominal resolution</li></ul>

LECO GCxGC FLUX flow modulator

Flux GC×GC flow modulator simplifies GC×GC analysis using diverting flow principles. It offers robust, cost-effective modulation without cryogens, ideal for complex, concentrated samples.

<p><strong>Our innovative Flux GC×GC flow modulator was designed with one goal in mind—to make GC×GC more routine, accessible, and easier for you. The flow modulator's concept is based on the sound and easily understood principles first articulated by Seeley et al. on diverting flow. This extraordinarily simple design comprising of a cross shape and sideways T, is not only easy to setup and get started, but its ease-of-use makes it the most cost-effective option for GC×GC analysis.</strong></p><p>This flow-based modulator is perfect for those who want to perform robust GC×GC analysis, but who don't need the sensitivity of standard quad jet thermal modulation. Ideal samples should be complex, but relatively concentrated. Appropriate applications include petroleum and fragrance analyses such as the classic weathered crude oil example pictured below, which shows a GC×GC plot generated on our Pegasus® BT platform using the Flux flow modulator.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ee943ea0acb34a8d9c5b72e7ace10666/obrazek_l.webp" alt="LECO GCxGC FLUX flow modulator" width="957" height="523"></p><h4><strong>Theory of Operation: Diverting Flow</strong></h4><p>The first and secondary capillary columns are connected together through a simple tube with a fixed gap between the columns. A flow of gas (helium) is then used to inject into the second column or divert to waste. The precision timing and flows are all handled by our integrated software, therefore you just have to click one button to setup and begin performing flow modulation GC×GC on our Pegasus BT platform.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/508b477dd1604d15855f26d786d5b1e4/obrazek_l.webp" alt="LECO GCxGC FLUX flow modulator" width="1026" height="488"></p><p>Furthermore, no complex spreadsheets are needed to understand your method. This simple and robust design does not require cryogens to carry out GC×GC, which saves time and boosts efficiency in your lab.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/6796d4581c894291b9fab0088753cb8b/obrazek_l.webp" alt="LECO GCxGC FLUX flow modulator" width="918" height="545"></p>

LECO QUADJET Thermal Modulator

Consumable-free dual-stage thermal jet modulator for GC×GC delivering on-column cryo-focusing, higher peak detectability, superior separation, and reliable performance without liquid nitrogen.

<p><strong>The QUADJET Thermal Modulator from </strong><span><strong>LECO</strong></span><strong> delivers industry-leading performance for comprehensive two-dimensional gas chromatography (GC×GC). Compared to alternative thermal or valve-based modulators, QUADJET stands out for its exceptional ruggedness, long-term reliability, and superior modulation efficiency.</strong></p><p>This GC×GC modulation system uses a <strong>dual-stage thermal jet modulator</strong> positioned between the first- and second-dimension columns. The design enables true <strong>on-column cryo-focusing</strong>, significantly enhancing peak sharpness, detectability, and separation power—especially for co-eluting compounds in complex sample matrices.</p><h3><strong>Key benefits</strong></h3><ul><li><strong>Highest modulation performance for GC×GC</strong><br>Enhances peak detectability and improves separation of co-eluting compounds.</li><li><strong>Dual-stage thermal jet design</strong><br>Provides efficient trapping and re-injection between columns.</li><li><strong>On-column cryo-focusing</strong><br>Improves sensitivity and separation of closely eluting analytes.</li><li><strong>Exceptional robustness and reliability</strong><br>Designed for routine, long-term GC×GC operation.</li></ul><h3><strong>Thermal modulation without liquid nitrogen</strong></h3><p>Unlike traditional cryogenic modulators, the <strong>QUADJET thermal modulator is consumable-free</strong>. It delivers the full performance benefits of thermal modulation <strong>without the need for liquid nitrogen</strong>, eliminating cryogen costs, logistical complexity, and downtime—while maintaining consistent, high-quality results.</p><p>The QUADJET Thermal Modulator is an ideal choice for laboratories seeking <strong>maximum GC×GC performance with minimal operational burden</strong>, particularly in demanding applications involving highly complex samples.</p>

LECO Chemical Ionization Source

Accurate-mass chemical ionization (HR-CI) for the Pegasus GC-HRT+ enables confident molecular ion confirmation, improved EI library matches, and reliable elemental formula generation for unknown compounds.

<p><strong>Confirm your unknowns with accurate mass chemical ionization (HR-CI), a new option for the </strong><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/38"><strong>Pegasus GC-HRT+</strong></a><strong>. The Pegasus GC-HRT+ is available with both electron ionization (EI) and HR-CI sources, offering you the option of comparison with classical library spectra (EI) and superior preservation of the molecular ion (HR-CI).</strong></p><h3><strong>Benefits of Positive ion Chemical Ionization</strong></h3><ul><li>Confirmation of molecular ions</li><li>More confidence in EI library matches</li><li>Propose chemical formulae for unknown or novel compounds</li><li>Reduce possible formulae with accurate mass data</li></ul><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/LECO_Chemical_Ionization_Source_bb19256163.jpg" alt="LECO Chemical Ionization Source" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_LECO_Chemical_Ionization_Source_bb19256163.jpg 245w," sizes="100vw" width="1696" height="644"></p><p>The spectral transformations illustrated above compare and - . The left side is an example from a mouse liver extract,EI HR CI where soft ionization allows for confident confirmation of a marker in glycemic variability for individuals with type 2 diabetes. The right side demonstrates how - is ideal for forensic drug analysis, as drugs are constantly evolving andHR CI often not present in commercially available libraries.</p><h3><strong>Standard Features</strong></h3><ul><li>Benzophenone 1 pg sensitivity</li><li>Automated reagent gas flow optimization</li><li>Support for standard CI gases: methane, isobutane, and ammonia, PLUS “choose your own”</li><li>Uncompromised MS performance: speed, accuracy and resolution all at the same time, regardless of intensity</li></ul>

LECO L-PAL3 GC Autosampler

LECO L-PAL3 GC Autosampler delivers flexible, discrimination-free GC injections with automated liquid, headspace, SPME, and ITEX sampling, high vial capacity, and minimal carryover.

<p><strong>Available exclusively from LECO, the L-PAL3 GC Autosampler is a highly robust, fully integrated autosampling platform designed for high flexibility and reliability in gas chromatography workflows. Based on proven CTC PAL3 technology, it supports discrimination-free ultrafast GC injections and minimizes carryover while ensuring precise and reproducible sample handling.</strong></p><p>Key innovations include <strong>automatic tool exchange (ATX)</strong> for seamless switching between liquid, headspace, SPME, and ITEX sampling modes, <strong>vial bottom sensing</strong> to prevent mis-injections, and high vial capacity for unattended operation. These features allow analysts to focus on compound identification without downtime or uncertainty.</p><h3><strong>Key Features</strong></h3><ul><li>Allows for automation of up to 162 two mL samples, or 45 ten/twenty mL samples.</li><li>Discrimination-free injection speeds with complete injection cycle time down to 100 milliseconds.</li><li>Bottom-sensing technology ensures that even very small volumes can be sampled.</li><li>Four separate models available so you may configure your package based on your autosampler needs.</li><li>Automatic Tool Exchange (ATX) allows users to switch between liquid, SPME, and headspace seamlessly.</li><li>96 to 384 well plate sampling supported; requires foil cutter.</li><li>Now available with Peltier cooled racks.</li></ul><h3><strong>Available Configurations</strong></h3><h4><strong>L-PAL3 GC Autosampler – Liquid Injections</strong></h4><ul><li>3-axis CTC-based autosampler/injector</li><li>Standard liquid injections</li><li>5-position solvent wash station</li><li>Liquid syringe tool</li><li>GC mounting kit</li><li>Single tray holder with <strong>3 trays × 54 positions (2 mL vials)</strong></li><li><strong>Non-upgradable configuration</strong></li></ul><h4><strong>L-PAL3 GC Autosampler – Liquid &amp; Headspace Injections</strong></h4><ul><li>Liquid and static headspace injections</li><li>Heated agitator</li><li>5-position solvent wash station</li><li>Liquid syringe tool + heated headspace syringe tool</li><li>GC mounting kit</li><li>Two tray holders:<ul><li><strong>3 × 54 positions (2 mL vials)</strong></li><li><strong>3 × 15 positions (10/20 mL vials)</strong></li></ul></li><li><strong>Manual tool exchange</strong> between liquid and headspace modes</li></ul><h4><strong>ITEX Dynamic Headspace Tool</strong></h4><ul><li>Rapid, sensitive enrichment of volatile and semi-volatile compounds</li><li>Suitable for solid, liquid, and gaseous samples</li><li>Choice of adsorbents for optimal sensitivity</li><li>No sample loops, transfer lines, or valves → minimal contamination risk</li><li>ATX enables <strong>Headspace, SPME, and ITEX</strong> within a single sequence</li></ul><h4><strong>L-PAL3 GC Autosampler – Liquid &amp; SPME Injections</strong></h4><ul><li>Liquid injections and all SPME modes (immersion, headspace)</li><li>Heated agitator</li><li>5-position solvent wash station</li><li>Liquid syringe tool + SPME fiber tools</li><li>SPME fiber conditioning station</li><li>GC mounting kit</li><li>Two tray holders:<ul><li><strong>3 × 54 positions (2 mL vials)</strong></li><li><strong>3 × 15 positions (10/20 mL vials)</strong></li></ul></li><li><strong>Manual tool exchange</strong> between liquid and SPME modes</li></ul><h3><strong>L-PAL3 GC Autosampler – Liquid, Headspace &amp; SPME</strong></h3><ul><li>Fully automated switching between liquid, headspace, and SPME</li><li>Heated agitator</li><li>5-position solvent wash station</li><li>Tools for liquid syringe, headspace syringe, and SPME fibers</li><li>SPME fiber conditioning station</li><li>GC mounting kit</li><li>Two tray holders:<ul><li><strong>3 × 54 positions (2 mL vials)</strong></li><li><strong>3 × 15 positions (10/20 mL vials)</strong></li></ul></li></ul>

LECO Simply GC×GC®

Simply GC×GC from LECO guides users through the steps of creating an optimized GC×GC method or converting an existing 1D GC method for complex samples.

<p><strong>Simply GC×GC from </strong><span><strong>LECO</strong></span><strong> is a free tool designed to walk users through the steps of creating an optimized GC×GC method for complex samples.</strong></p><p>The tool allows users to <strong>create a GC×GC method from scratch</strong> or <strong>convert an existing 1D GC method to GC×GC</strong>.</p><p>Simply GC×GC provides <strong>logical, step-by-step instructions</strong>, for example for:</p><ul><li>setting the <strong>secondary oven offset</strong>,</li><li>setting the <strong>second-dimension column length</strong>,</li><li><strong>experimentally evaluating stationary phases and peak capacity</strong>.</li></ul><p>Simply GC×GC takes a simple approach to GC×GC and helps users avoid unnecessary testing while streamlining the method development cycle.</p>

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